1 #ifndef _LINUX_MMZONE_H
2 #define _LINUX_MMZONE_H
3
4 #ifndef __ASSEMBLY__
5 #ifndef __GENERATING_BOUNDS_H
6
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/wait.h>
10 #include <linux/bitops.h>
11 #include <linux/cache.h>
12 #include <linux/threads.h>
13 #include <linux/numa.h>
14 #include <linux/init.h>
15 #include <linux/seqlock.h>
16 #include <linux/nodemask.h>
17 #include <linux/pageblock-flags.h>
18 #include <linux/bounds.h>
19 #include <asm/atomic.h>
20 #include <asm/page.h>
21
22 /* Free memory management - zoned buddy allocator. */
23 #ifndef CONFIG_FORCE_MAX_ZONEORDER
24 #define MAX_ORDER 11
25 #else
26 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
27 #endif
28 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
29
30 /*
31 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
32 * costly to service. That is between allocation orders which should
33 * coelesce naturally under reasonable reclaim pressure and those which
34 * will not.
35 */
36 #define PAGE_ALLOC_COSTLY_ORDER 3
37
38 #define MIGRATE_UNMOVABLE 0
39 #define MIGRATE_RECLAIMABLE 1
40 #define MIGRATE_MOVABLE 2
41 #define MIGRATE_RESERVE 3
42 #define MIGRATE_ISOLATE 4 /* can't allocate from here */
43 #define MIGRATE_TYPES 5
44
45 #define for_each_migratetype_order(order, type) \
46 for (order = 0; order < MAX_ORDER; order++) \
47 for (type = 0; type < MIGRATE_TYPES; type++)
48
49 extern int page_group_by_mobility_disabled;
50
get_pageblock_migratetype(struct page * page)51 static inline int get_pageblock_migratetype(struct page *page)
52 {
53 if (unlikely(page_group_by_mobility_disabled))
54 return MIGRATE_UNMOVABLE;
55
56 return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
57 }
58
59 struct free_area {
60 struct list_head free_list[MIGRATE_TYPES];
61 unsigned long nr_free;
62 };
63
64 struct pglist_data;
65
66 /*
67 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
68 * So add a wild amount of padding here to ensure that they fall into separate
69 * cachelines. There are very few zone structures in the machine, so space
70 * consumption is not a concern here.
71 */
72 #if defined(CONFIG_SMP)
73 struct zone_padding {
74 char x[0];
75 } ____cacheline_internodealigned_in_smp;
76 #define ZONE_PADDING(name) struct zone_padding name;
77 #else
78 #define ZONE_PADDING(name)
79 #endif
80
81 enum zone_stat_item {
82 /* First 128 byte cacheline (assuming 64 bit words) */
83 NR_FREE_PAGES,
84 NR_LRU_BASE,
85 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
86 NR_ACTIVE_ANON, /* " " " " " */
87 NR_INACTIVE_FILE, /* " " " " " */
88 NR_ACTIVE_FILE, /* " " " " " */
89 #ifdef CONFIG_UNEVICTABLE_LRU
90 NR_UNEVICTABLE, /* " " " " " */
91 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
92 #else
93 NR_UNEVICTABLE = NR_ACTIVE_FILE, /* avoid compiler errors in dead code */
94 NR_MLOCK = NR_ACTIVE_FILE,
95 #endif
96 NR_ANON_PAGES, /* Mapped anonymous pages */
97 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
98 only modified from process context */
99 NR_FILE_PAGES,
100 NR_FILE_DIRTY,
101 NR_WRITEBACK,
102 NR_SLAB_RECLAIMABLE,
103 NR_SLAB_UNRECLAIMABLE,
104 NR_PAGETABLE, /* used for pagetables */
105 NR_UNSTABLE_NFS, /* NFS unstable pages */
106 NR_BOUNCE,
107 NR_VMSCAN_WRITE,
108 /* Second 128 byte cacheline */
109 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
110 #ifdef CONFIG_NUMA
111 NUMA_HIT, /* allocated in intended node */
112 NUMA_MISS, /* allocated in non intended node */
113 NUMA_FOREIGN, /* was intended here, hit elsewhere */
114 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
115 NUMA_LOCAL, /* allocation from local node */
116 NUMA_OTHER, /* allocation from other node */
117 #endif
118 NR_VM_ZONE_STAT_ITEMS };
119
120 /*
121 * We do arithmetic on the LRU lists in various places in the code,
122 * so it is important to keep the active lists LRU_ACTIVE higher in
123 * the array than the corresponding inactive lists, and to keep
124 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
125 *
126 * This has to be kept in sync with the statistics in zone_stat_item
127 * above and the descriptions in vmstat_text in mm/vmstat.c
128 */
129 #define LRU_BASE 0
130 #define LRU_ACTIVE 1
131 #define LRU_FILE 2
132
133 enum lru_list {
134 LRU_INACTIVE_ANON = LRU_BASE,
135 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
136 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
137 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
138 #ifdef CONFIG_UNEVICTABLE_LRU
139 LRU_UNEVICTABLE,
140 #else
141 LRU_UNEVICTABLE = LRU_ACTIVE_FILE, /* avoid compiler errors in dead code */
142 #endif
143 NR_LRU_LISTS
144 };
145
146 #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
147
148 #define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
149
is_file_lru(enum lru_list l)150 static inline int is_file_lru(enum lru_list l)
151 {
152 return (l == LRU_INACTIVE_FILE || l == LRU_ACTIVE_FILE);
153 }
154
is_active_lru(enum lru_list l)155 static inline int is_active_lru(enum lru_list l)
156 {
157 return (l == LRU_ACTIVE_ANON || l == LRU_ACTIVE_FILE);
158 }
159
is_unevictable_lru(enum lru_list l)160 static inline int is_unevictable_lru(enum lru_list l)
161 {
162 #ifdef CONFIG_UNEVICTABLE_LRU
163 return (l == LRU_UNEVICTABLE);
164 #else
165 return 0;
166 #endif
167 }
168
169 struct per_cpu_pages {
170 int count; /* number of pages in the list */
171 int high; /* high watermark, emptying needed */
172 int batch; /* chunk size for buddy add/remove */
173 struct list_head list; /* the list of pages */
174 };
175
176 struct per_cpu_pageset {
177 struct per_cpu_pages pcp;
178 #ifdef CONFIG_NUMA
179 s8 expire;
180 #endif
181 #ifdef CONFIG_SMP
182 s8 stat_threshold;
183 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
184 #endif
185 } ____cacheline_aligned_in_smp;
186
187 #ifdef CONFIG_NUMA
188 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
189 #else
190 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
191 #endif
192
193 #endif /* !__GENERATING_BOUNDS.H */
194
195 enum zone_type {
196 #ifdef CONFIG_ZONE_DMA
197 /*
198 * ZONE_DMA is used when there are devices that are not able
199 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
200 * carve out the portion of memory that is needed for these devices.
201 * The range is arch specific.
202 *
203 * Some examples
204 *
205 * Architecture Limit
206 * ---------------------------
207 * parisc, ia64, sparc <4G
208 * s390 <2G
209 * arm Various
210 * alpha Unlimited or 0-16MB.
211 *
212 * i386, x86_64 and multiple other arches
213 * <16M.
214 */
215 ZONE_DMA,
216 #endif
217 #ifdef CONFIG_ZONE_DMA32
218 /*
219 * x86_64 needs two ZONE_DMAs because it supports devices that are
220 * only able to do DMA to the lower 16M but also 32 bit devices that
221 * can only do DMA areas below 4G.
222 */
223 ZONE_DMA32,
224 #endif
225 /*
226 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
227 * performed on pages in ZONE_NORMAL if the DMA devices support
228 * transfers to all addressable memory.
229 */
230 ZONE_NORMAL,
231 #ifdef CONFIG_HIGHMEM
232 /*
233 * A memory area that is only addressable by the kernel through
234 * mapping portions into its own address space. This is for example
235 * used by i386 to allow the kernel to address the memory beyond
236 * 900MB. The kernel will set up special mappings (page
237 * table entries on i386) for each page that the kernel needs to
238 * access.
239 */
240 ZONE_HIGHMEM,
241 #endif
242 ZONE_MOVABLE,
243 __MAX_NR_ZONES
244 };
245
246 #ifndef __GENERATING_BOUNDS_H
247
248 /*
249 * When a memory allocation must conform to specific limitations (such
250 * as being suitable for DMA) the caller will pass in hints to the
251 * allocator in the gfp_mask, in the zone modifier bits. These bits
252 * are used to select a priority ordered list of memory zones which
253 * match the requested limits. See gfp_zone() in include/linux/gfp.h
254 */
255
256 #if MAX_NR_ZONES < 2
257 #define ZONES_SHIFT 0
258 #elif MAX_NR_ZONES <= 2
259 #define ZONES_SHIFT 1
260 #elif MAX_NR_ZONES <= 4
261 #define ZONES_SHIFT 2
262 #else
263 #error ZONES_SHIFT -- too many zones configured adjust calculation
264 #endif
265
266 struct zone_reclaim_stat {
267 /*
268 * The pageout code in vmscan.c keeps track of how many of the
269 * mem/swap backed and file backed pages are refeferenced.
270 * The higher the rotated/scanned ratio, the more valuable
271 * that cache is.
272 *
273 * The anon LRU stats live in [0], file LRU stats in [1]
274 */
275 unsigned long recent_rotated[2];
276 unsigned long recent_scanned[2];
277 };
278
279 struct zone {
280 /* Fields commonly accessed by the page allocator */
281 unsigned long pages_min, pages_low, pages_high;
282 /*
283 * We don't know if the memory that we're going to allocate will be freeable
284 * or/and it will be released eventually, so to avoid totally wasting several
285 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
286 * to run OOM on the lower zones despite there's tons of freeable ram
287 * on the higher zones). This array is recalculated at runtime if the
288 * sysctl_lowmem_reserve_ratio sysctl changes.
289 */
290 unsigned long lowmem_reserve[MAX_NR_ZONES];
291
292 #ifdef CONFIG_NUMA
293 int node;
294 /*
295 * zone reclaim becomes active if more unmapped pages exist.
296 */
297 unsigned long min_unmapped_pages;
298 unsigned long min_slab_pages;
299 struct per_cpu_pageset *pageset[NR_CPUS];
300 #else
301 struct per_cpu_pageset pageset[NR_CPUS];
302 #endif
303 /*
304 * free areas of different sizes
305 */
306 spinlock_t lock;
307 #ifdef CONFIG_MEMORY_HOTPLUG
308 /* see spanned/present_pages for more description */
309 seqlock_t span_seqlock;
310 #endif
311 struct free_area free_area[MAX_ORDER];
312
313 #ifndef CONFIG_SPARSEMEM
314 /*
315 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
316 * In SPARSEMEM, this map is stored in struct mem_section
317 */
318 unsigned long *pageblock_flags;
319 #endif /* CONFIG_SPARSEMEM */
320
321
322 ZONE_PADDING(_pad1_)
323
324 /* Fields commonly accessed by the page reclaim scanner */
325 spinlock_t lru_lock;
326 struct {
327 struct list_head list;
328 unsigned long nr_scan;
329 } lru[NR_LRU_LISTS];
330
331 struct zone_reclaim_stat reclaim_stat;
332
333 unsigned long pages_scanned; /* since last reclaim */
334 unsigned long flags; /* zone flags, see below */
335
336 /* Zone statistics */
337 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
338
339 /*
340 * prev_priority holds the scanning priority for this zone. It is
341 * defined as the scanning priority at which we achieved our reclaim
342 * target at the previous try_to_free_pages() or balance_pgdat()
343 * invokation.
344 *
345 * We use prev_priority as a measure of how much stress page reclaim is
346 * under - it drives the swappiness decision: whether to unmap mapped
347 * pages.
348 *
349 * Access to both this field is quite racy even on uniprocessor. But
350 * it is expected to average out OK.
351 */
352 int prev_priority;
353
354 /*
355 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
356 * this zone's LRU. Maintained by the pageout code.
357 */
358 unsigned int inactive_ratio;
359
360
361 ZONE_PADDING(_pad2_)
362 /* Rarely used or read-mostly fields */
363
364 /*
365 * wait_table -- the array holding the hash table
366 * wait_table_hash_nr_entries -- the size of the hash table array
367 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
368 *
369 * The purpose of all these is to keep track of the people
370 * waiting for a page to become available and make them
371 * runnable again when possible. The trouble is that this
372 * consumes a lot of space, especially when so few things
373 * wait on pages at a given time. So instead of using
374 * per-page waitqueues, we use a waitqueue hash table.
375 *
376 * The bucket discipline is to sleep on the same queue when
377 * colliding and wake all in that wait queue when removing.
378 * When something wakes, it must check to be sure its page is
379 * truly available, a la thundering herd. The cost of a
380 * collision is great, but given the expected load of the
381 * table, they should be so rare as to be outweighed by the
382 * benefits from the saved space.
383 *
384 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
385 * primary users of these fields, and in mm/page_alloc.c
386 * free_area_init_core() performs the initialization of them.
387 */
388 wait_queue_head_t * wait_table;
389 unsigned long wait_table_hash_nr_entries;
390 unsigned long wait_table_bits;
391
392 /*
393 * Discontig memory support fields.
394 */
395 struct pglist_data *zone_pgdat;
396 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
397 unsigned long zone_start_pfn;
398
399 /*
400 * zone_start_pfn, spanned_pages and present_pages are all
401 * protected by span_seqlock. It is a seqlock because it has
402 * to be read outside of zone->lock, and it is done in the main
403 * allocator path. But, it is written quite infrequently.
404 *
405 * The lock is declared along with zone->lock because it is
406 * frequently read in proximity to zone->lock. It's good to
407 * give them a chance of being in the same cacheline.
408 */
409 unsigned long spanned_pages; /* total size, including holes */
410 unsigned long present_pages; /* amount of memory (excluding holes) */
411
412 /*
413 * rarely used fields:
414 */
415 const char *name;
416 } ____cacheline_internodealigned_in_smp;
417
418 typedef enum {
419 ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
420 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
421 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
422 } zone_flags_t;
423
zone_set_flag(struct zone * zone,zone_flags_t flag)424 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
425 {
426 set_bit(flag, &zone->flags);
427 }
428
zone_test_and_set_flag(struct zone * zone,zone_flags_t flag)429 static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
430 {
431 return test_and_set_bit(flag, &zone->flags);
432 }
433
zone_clear_flag(struct zone * zone,zone_flags_t flag)434 static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
435 {
436 clear_bit(flag, &zone->flags);
437 }
438
zone_is_all_unreclaimable(const struct zone * zone)439 static inline int zone_is_all_unreclaimable(const struct zone *zone)
440 {
441 return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags);
442 }
443
zone_is_reclaim_locked(const struct zone * zone)444 static inline int zone_is_reclaim_locked(const struct zone *zone)
445 {
446 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
447 }
448
zone_is_oom_locked(const struct zone * zone)449 static inline int zone_is_oom_locked(const struct zone *zone)
450 {
451 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
452 }
453
454 /*
455 * The "priority" of VM scanning is how much of the queues we will scan in one
456 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
457 * queues ("queue_length >> 12") during an aging round.
458 */
459 #define DEF_PRIORITY 12
460
461 /* Maximum number of zones on a zonelist */
462 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
463
464 #ifdef CONFIG_NUMA
465
466 /*
467 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
468 * allocations to a single node for GFP_THISNODE.
469 *
470 * [0] : Zonelist with fallback
471 * [1] : No fallback (GFP_THISNODE)
472 */
473 #define MAX_ZONELISTS 2
474
475
476 /*
477 * We cache key information from each zonelist for smaller cache
478 * footprint when scanning for free pages in get_page_from_freelist().
479 *
480 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
481 * up short of free memory since the last time (last_fullzone_zap)
482 * we zero'd fullzones.
483 * 2) The array z_to_n[] maps each zone in the zonelist to its node
484 * id, so that we can efficiently evaluate whether that node is
485 * set in the current tasks mems_allowed.
486 *
487 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
488 * indexed by a zones offset in the zonelist zones[] array.
489 *
490 * The get_page_from_freelist() routine does two scans. During the
491 * first scan, we skip zones whose corresponding bit in 'fullzones'
492 * is set or whose corresponding node in current->mems_allowed (which
493 * comes from cpusets) is not set. During the second scan, we bypass
494 * this zonelist_cache, to ensure we look methodically at each zone.
495 *
496 * Once per second, we zero out (zap) fullzones, forcing us to
497 * reconsider nodes that might have regained more free memory.
498 * The field last_full_zap is the time we last zapped fullzones.
499 *
500 * This mechanism reduces the amount of time we waste repeatedly
501 * reexaming zones for free memory when they just came up low on
502 * memory momentarilly ago.
503 *
504 * The zonelist_cache struct members logically belong in struct
505 * zonelist. However, the mempolicy zonelists constructed for
506 * MPOL_BIND are intentionally variable length (and usually much
507 * shorter). A general purpose mechanism for handling structs with
508 * multiple variable length members is more mechanism than we want
509 * here. We resort to some special case hackery instead.
510 *
511 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
512 * part because they are shorter), so we put the fixed length stuff
513 * at the front of the zonelist struct, ending in a variable length
514 * zones[], as is needed by MPOL_BIND.
515 *
516 * Then we put the optional zonelist cache on the end of the zonelist
517 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
518 * the fixed length portion at the front of the struct. This pointer
519 * both enables us to find the zonelist cache, and in the case of
520 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
521 * to know that the zonelist cache is not there.
522 *
523 * The end result is that struct zonelists come in two flavors:
524 * 1) The full, fixed length version, shown below, and
525 * 2) The custom zonelists for MPOL_BIND.
526 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
527 *
528 * Even though there may be multiple CPU cores on a node modifying
529 * fullzones or last_full_zap in the same zonelist_cache at the same
530 * time, we don't lock it. This is just hint data - if it is wrong now
531 * and then, the allocator will still function, perhaps a bit slower.
532 */
533
534
535 struct zonelist_cache {
536 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
537 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
538 unsigned long last_full_zap; /* when last zap'd (jiffies) */
539 };
540 #else
541 #define MAX_ZONELISTS 1
542 struct zonelist_cache;
543 #endif
544
545 /*
546 * This struct contains information about a zone in a zonelist. It is stored
547 * here to avoid dereferences into large structures and lookups of tables
548 */
549 struct zoneref {
550 struct zone *zone; /* Pointer to actual zone */
551 int zone_idx; /* zone_idx(zoneref->zone) */
552 };
553
554 /*
555 * One allocation request operates on a zonelist. A zonelist
556 * is a list of zones, the first one is the 'goal' of the
557 * allocation, the other zones are fallback zones, in decreasing
558 * priority.
559 *
560 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
561 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
562 * *
563 * To speed the reading of the zonelist, the zonerefs contain the zone index
564 * of the entry being read. Helper functions to access information given
565 * a struct zoneref are
566 *
567 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
568 * zonelist_zone_idx() - Return the index of the zone for an entry
569 * zonelist_node_idx() - Return the index of the node for an entry
570 */
571 struct zonelist {
572 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
573 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
574 #ifdef CONFIG_NUMA
575 struct zonelist_cache zlcache; // optional ...
576 #endif
577 };
578
579 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
580 struct node_active_region {
581 unsigned long start_pfn;
582 unsigned long end_pfn;
583 int nid;
584 };
585 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
586
587 #ifndef CONFIG_DISCONTIGMEM
588 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
589 extern struct page *mem_map;
590 #endif
591
592 /*
593 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
594 * (mostly NUMA machines?) to denote a higher-level memory zone than the
595 * zone denotes.
596 *
597 * On NUMA machines, each NUMA node would have a pg_data_t to describe
598 * it's memory layout.
599 *
600 * Memory statistics and page replacement data structures are maintained on a
601 * per-zone basis.
602 */
603 struct bootmem_data;
604 typedef struct pglist_data {
605 struct zone node_zones[MAX_NR_ZONES];
606 struct zonelist node_zonelists[MAX_ZONELISTS];
607 int nr_zones;
608 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
609 struct page *node_mem_map;
610 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
611 struct page_cgroup *node_page_cgroup;
612 #endif
613 #endif
614 struct bootmem_data *bdata;
615 #ifdef CONFIG_MEMORY_HOTPLUG
616 /*
617 * Must be held any time you expect node_start_pfn, node_present_pages
618 * or node_spanned_pages stay constant. Holding this will also
619 * guarantee that any pfn_valid() stays that way.
620 *
621 * Nests above zone->lock and zone->size_seqlock.
622 */
623 spinlock_t node_size_lock;
624 #endif
625 unsigned long node_start_pfn;
626 unsigned long node_present_pages; /* total number of physical pages */
627 unsigned long node_spanned_pages; /* total size of physical page
628 range, including holes */
629 int node_id;
630 wait_queue_head_t kswapd_wait;
631 struct task_struct *kswapd;
632 int kswapd_max_order;
633 } pg_data_t;
634
635 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
636 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
637 #ifdef CONFIG_FLAT_NODE_MEM_MAP
638 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
639 #else
640 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
641 #endif
642 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
643
644 #include <linux/memory_hotplug.h>
645
646 void get_zone_counts(unsigned long *active, unsigned long *inactive,
647 unsigned long *free);
648 void build_all_zonelists(void);
649 void wakeup_kswapd(struct zone *zone, int order);
650 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
651 int classzone_idx, int alloc_flags);
652 enum memmap_context {
653 MEMMAP_EARLY,
654 MEMMAP_HOTPLUG,
655 };
656 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
657 unsigned long size,
658 enum memmap_context context);
659
660 #ifdef CONFIG_HAVE_MEMORY_PRESENT
661 void memory_present(int nid, unsigned long start, unsigned long end);
662 #else
memory_present(int nid,unsigned long start,unsigned long end)663 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
664 #endif
665
666 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
667 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
668 #endif
669
670 /*
671 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
672 */
673 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
674
populated_zone(struct zone * zone)675 static inline int populated_zone(struct zone *zone)
676 {
677 return (!!zone->present_pages);
678 }
679
680 extern int movable_zone;
681
zone_movable_is_highmem(void)682 static inline int zone_movable_is_highmem(void)
683 {
684 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
685 return movable_zone == ZONE_HIGHMEM;
686 #else
687 return 0;
688 #endif
689 }
690
is_highmem_idx(enum zone_type idx)691 static inline int is_highmem_idx(enum zone_type idx)
692 {
693 #ifdef CONFIG_HIGHMEM
694 return (idx == ZONE_HIGHMEM ||
695 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
696 #else
697 return 0;
698 #endif
699 }
700
is_normal_idx(enum zone_type idx)701 static inline int is_normal_idx(enum zone_type idx)
702 {
703 return (idx == ZONE_NORMAL);
704 }
705
706 /**
707 * is_highmem - helper function to quickly check if a struct zone is a
708 * highmem zone or not. This is an attempt to keep references
709 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
710 * @zone - pointer to struct zone variable
711 */
is_highmem(struct zone * zone)712 static inline int is_highmem(struct zone *zone)
713 {
714 #ifdef CONFIG_HIGHMEM
715 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
716 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
717 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
718 zone_movable_is_highmem());
719 #else
720 return 0;
721 #endif
722 }
723
is_normal(struct zone * zone)724 static inline int is_normal(struct zone *zone)
725 {
726 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
727 }
728
is_dma32(struct zone * zone)729 static inline int is_dma32(struct zone *zone)
730 {
731 #ifdef CONFIG_ZONE_DMA32
732 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
733 #else
734 return 0;
735 #endif
736 }
737
is_dma(struct zone * zone)738 static inline int is_dma(struct zone *zone)
739 {
740 #ifdef CONFIG_ZONE_DMA
741 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
742 #else
743 return 0;
744 #endif
745 }
746
747 /* These two functions are used to setup the per zone pages min values */
748 struct ctl_table;
749 struct file;
750 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
751 void __user *, size_t *, loff_t *);
752 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
753 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
754 void __user *, size_t *, loff_t *);
755 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
756 void __user *, size_t *, loff_t *);
757 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
758 struct file *, void __user *, size_t *, loff_t *);
759 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
760 struct file *, void __user *, size_t *, loff_t *);
761
762 extern int numa_zonelist_order_handler(struct ctl_table *, int,
763 struct file *, void __user *, size_t *, loff_t *);
764 extern char numa_zonelist_order[];
765 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
766
767 #include <linux/topology.h>
768 /* Returns the number of the current Node. */
769 #ifndef numa_node_id
770 #define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
771 #endif
772
773 #ifndef CONFIG_NEED_MULTIPLE_NODES
774
775 extern struct pglist_data contig_page_data;
776 #define NODE_DATA(nid) (&contig_page_data)
777 #define NODE_MEM_MAP(nid) mem_map
778
779 #else /* CONFIG_NEED_MULTIPLE_NODES */
780
781 #include <asm/mmzone.h>
782
783 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
784
785 extern struct pglist_data *first_online_pgdat(void);
786 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
787 extern struct zone *next_zone(struct zone *zone);
788
789 /**
790 * for_each_online_pgdat - helper macro to iterate over all online nodes
791 * @pgdat - pointer to a pg_data_t variable
792 */
793 #define for_each_online_pgdat(pgdat) \
794 for (pgdat = first_online_pgdat(); \
795 pgdat; \
796 pgdat = next_online_pgdat(pgdat))
797 /**
798 * for_each_zone - helper macro to iterate over all memory zones
799 * @zone - pointer to struct zone variable
800 *
801 * The user only needs to declare the zone variable, for_each_zone
802 * fills it in.
803 */
804 #define for_each_zone(zone) \
805 for (zone = (first_online_pgdat())->node_zones; \
806 zone; \
807 zone = next_zone(zone))
808
zonelist_zone(struct zoneref * zoneref)809 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
810 {
811 return zoneref->zone;
812 }
813
zonelist_zone_idx(struct zoneref * zoneref)814 static inline int zonelist_zone_idx(struct zoneref *zoneref)
815 {
816 return zoneref->zone_idx;
817 }
818
zonelist_node_idx(struct zoneref * zoneref)819 static inline int zonelist_node_idx(struct zoneref *zoneref)
820 {
821 #ifdef CONFIG_NUMA
822 /* zone_to_nid not available in this context */
823 return zoneref->zone->node;
824 #else
825 return 0;
826 #endif /* CONFIG_NUMA */
827 }
828
829 /**
830 * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point
831 * @z - The cursor used as a starting point for the search
832 * @highest_zoneidx - The zone index of the highest zone to return
833 * @nodes - An optional nodemask to filter the zonelist with
834 * @zone - The first suitable zone found is returned via this parameter
835 *
836 * This function returns the next zone at or below a given zone index that is
837 * within the allowed nodemask using a cursor as the starting point for the
838 * search. The zoneref returned is a cursor that represents the current zone
839 * being examined. It should be advanced by one before calling
840 * next_zones_zonelist again.
841 */
842 struct zoneref *next_zones_zonelist(struct zoneref *z,
843 enum zone_type highest_zoneidx,
844 nodemask_t *nodes,
845 struct zone **zone);
846
847 /**
848 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
849 * @zonelist - The zonelist to search for a suitable zone
850 * @highest_zoneidx - The zone index of the highest zone to return
851 * @nodes - An optional nodemask to filter the zonelist with
852 * @zone - The first suitable zone found is returned via this parameter
853 *
854 * This function returns the first zone at or below a given zone index that is
855 * within the allowed nodemask. The zoneref returned is a cursor that can be
856 * used to iterate the zonelist with next_zones_zonelist by advancing it by
857 * one before calling.
858 */
first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes,struct zone ** zone)859 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
860 enum zone_type highest_zoneidx,
861 nodemask_t *nodes,
862 struct zone **zone)
863 {
864 return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
865 zone);
866 }
867
868 /**
869 * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask
870 * @zone - The current zone in the iterator
871 * @z - The current pointer within zonelist->zones being iterated
872 * @zlist - The zonelist being iterated
873 * @highidx - The zone index of the highest zone to return
874 * @nodemask - Nodemask allowed by the allocator
875 *
876 * This iterator iterates though all zones at or below a given zone index and
877 * within a given nodemask
878 */
879 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
880 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
881 zone; \
882 z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
883
884 /**
885 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
886 * @zone - The current zone in the iterator
887 * @z - The current pointer within zonelist->zones being iterated
888 * @zlist - The zonelist being iterated
889 * @highidx - The zone index of the highest zone to return
890 *
891 * This iterator iterates though all zones at or below a given zone index.
892 */
893 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
894 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
895
896 #ifdef CONFIG_SPARSEMEM
897 #include <asm/sparsemem.h>
898 #endif
899
900 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
901 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
early_pfn_to_nid(unsigned long pfn)902 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
903 {
904 return 0;
905 }
906 #endif
907
908 #ifdef CONFIG_FLATMEM
909 #define pfn_to_nid(pfn) (0)
910 #endif
911
912 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
913 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
914
915 #ifdef CONFIG_SPARSEMEM
916
917 /*
918 * SECTION_SHIFT #bits space required to store a section #
919 *
920 * PA_SECTION_SHIFT physical address to/from section number
921 * PFN_SECTION_SHIFT pfn to/from section number
922 */
923 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
924
925 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
926 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
927
928 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
929
930 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
931 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
932
933 #define SECTION_BLOCKFLAGS_BITS \
934 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
935
936 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
937 #error Allocator MAX_ORDER exceeds SECTION_SIZE
938 #endif
939
940 struct page;
941 struct page_cgroup;
942 struct mem_section {
943 /*
944 * This is, logically, a pointer to an array of struct
945 * pages. However, it is stored with some other magic.
946 * (see sparse.c::sparse_init_one_section())
947 *
948 * Additionally during early boot we encode node id of
949 * the location of the section here to guide allocation.
950 * (see sparse.c::memory_present())
951 *
952 * Making it a UL at least makes someone do a cast
953 * before using it wrong.
954 */
955 unsigned long section_mem_map;
956
957 /* See declaration of similar field in struct zone */
958 unsigned long *pageblock_flags;
959 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
960 /*
961 * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
962 * section. (see memcontrol.h/page_cgroup.h about this.)
963 */
964 struct page_cgroup *page_cgroup;
965 unsigned long pad;
966 #endif
967 };
968
969 #ifdef CONFIG_SPARSEMEM_EXTREME
970 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
971 #else
972 #define SECTIONS_PER_ROOT 1
973 #endif
974
975 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
976 #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
977 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
978
979 #ifdef CONFIG_SPARSEMEM_EXTREME
980 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
981 #else
982 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
983 #endif
984
__nr_to_section(unsigned long nr)985 static inline struct mem_section *__nr_to_section(unsigned long nr)
986 {
987 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
988 return NULL;
989 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
990 }
991 extern int __section_nr(struct mem_section* ms);
992 extern unsigned long usemap_size(void);
993
994 /*
995 * We use the lower bits of the mem_map pointer to store
996 * a little bit of information. There should be at least
997 * 3 bits here due to 32-bit alignment.
998 */
999 #define SECTION_MARKED_PRESENT (1UL<<0)
1000 #define SECTION_HAS_MEM_MAP (1UL<<1)
1001 #define SECTION_MAP_LAST_BIT (1UL<<2)
1002 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1003 #define SECTION_NID_SHIFT 2
1004
__section_mem_map_addr(struct mem_section * section)1005 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1006 {
1007 unsigned long map = section->section_mem_map;
1008 map &= SECTION_MAP_MASK;
1009 return (struct page *)map;
1010 }
1011
present_section(struct mem_section * section)1012 static inline int present_section(struct mem_section *section)
1013 {
1014 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1015 }
1016
present_section_nr(unsigned long nr)1017 static inline int present_section_nr(unsigned long nr)
1018 {
1019 return present_section(__nr_to_section(nr));
1020 }
1021
valid_section(struct mem_section * section)1022 static inline int valid_section(struct mem_section *section)
1023 {
1024 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1025 }
1026
valid_section_nr(unsigned long nr)1027 static inline int valid_section_nr(unsigned long nr)
1028 {
1029 return valid_section(__nr_to_section(nr));
1030 }
1031
__pfn_to_section(unsigned long pfn)1032 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1033 {
1034 return __nr_to_section(pfn_to_section_nr(pfn));
1035 }
1036
pfn_valid(unsigned long pfn)1037 static inline int pfn_valid(unsigned long pfn)
1038 {
1039 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1040 return 0;
1041 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1042 }
1043
pfn_present(unsigned long pfn)1044 static inline int pfn_present(unsigned long pfn)
1045 {
1046 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1047 return 0;
1048 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1049 }
1050
1051 /*
1052 * These are _only_ used during initialisation, therefore they
1053 * can use __initdata ... They could have names to indicate
1054 * this restriction.
1055 */
1056 #ifdef CONFIG_NUMA
1057 #define pfn_to_nid(pfn) \
1058 ({ \
1059 unsigned long __pfn_to_nid_pfn = (pfn); \
1060 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1061 })
1062 #else
1063 #define pfn_to_nid(pfn) (0)
1064 #endif
1065
1066 #define early_pfn_valid(pfn) pfn_valid(pfn)
1067 void sparse_init(void);
1068 #else
1069 #define sparse_init() do {} while (0)
1070 #define sparse_index_init(_sec, _nid) do {} while (0)
1071 #endif /* CONFIG_SPARSEMEM */
1072
1073 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1074 bool early_pfn_in_nid(unsigned long pfn, int nid);
1075 #else
1076 #define early_pfn_in_nid(pfn, nid) (1)
1077 #endif
1078
1079 #ifndef early_pfn_valid
1080 #define early_pfn_valid(pfn) (1)
1081 #endif
1082
1083 void memory_present(int nid, unsigned long start, unsigned long end);
1084 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1085
1086 /*
1087 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1088 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1089 * pfn_valid_within() should be used in this case; we optimise this away
1090 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1091 */
1092 #ifdef CONFIG_HOLES_IN_ZONE
1093 #define pfn_valid_within(pfn) pfn_valid(pfn)
1094 #else
1095 #define pfn_valid_within(pfn) (1)
1096 #endif
1097
1098 #endif /* !__GENERATING_BOUNDS.H */
1099 #endif /* !__ASSEMBLY__ */
1100 #endif /* _LINUX_MMZONE_H */
1101